BEIRUT (Reuters) - A barrel bomb killed a family of six in rebel-held eastern Aleppo early on Sunday, a war monitor, a rebel and two medics said, while rebel shelling killed seven children at a school in the government-held sector, state television reported.
The medics said the al-Baytounji family had suffocated to death because the barrel bomb, which fell in the Sakhour district at about midnight, had been laced with chlorine gas. The Syrian Observatory for Human Rights, which monitors the war, could not confirm that chlorine gas was used.
Rebel shelling killed at least seven children among 10 deaths in the Saria Hasoun school in al-Farqan district, Syrian state television and the Observatory reported.
Hundreds of people have been killed since Tuesday in one of the heaviest bombardments of the country's civil war, now in its sixth year, as the government and its allies attempt to quash resistance in Aleppo's rebel-held eastern zone.
Syria's military and Russia's air force had observed a unilateral pause in the bombardment of eastern Aleppo, except for on the frontlines, after a month-long offensive from late September to late October, but recommenced strikes on Tuesday.
An inquiry by the United Nations and the Organisation for the Prohibition of Chemical Weapons has found that Syrian government forces have used chlorine gas in barrel bombs at least three times during the war, though Damascus denies it.
Syria also denies using barrel bombs - improvised ordnance made by oil drums filled with high explosive and shrapnel and dropped from helicopters. Their use has been condemned by the United Nations for causing unnecessary suffering.
Staffan De Mistura, the envoy of the United Nations secretary general, arrived in Damascus for talks with Syrian Foreign Ministry officials on Sunday with Aleppo on the agenda.
Air strikes continued to hit several districts of eastern Aleppo early on Sunday, the Syrian Observatory for Human Rights, a Britain-based war monitor said, after at least 54 people were killed in bombing on Saturday.
The two medics identified the family in a film distributed online. It showed the corpses of its four children stretched out on a floor, their lips blue and dark marks around their open eyes.
One of the medics, Abu al-Abbas, has a colleague who lives on the same street, he said. Another was the manager of a hospital and said doctors had confirmed the cause of their death as gas poisoning. A rebel official, Zakaria al-Malahifji, from the Fastaqim group, also said they had been killed by gas.
The civil war pits President Bashar al-Assad backed by Russia's air force, Iran and Shi'ite militias against mostly Sunni rebels including groups supported by the United States, Turkey and Gulf monarchies.
Aleppo has become the focal point for fighting, as the army and its allies attempt to end insurgent resistance there, alternating intense bombardment and ground attacks with offers to rebels to quit the city during periods of reduced bombing.
The use of siege and bombardment tactics has previously forced rebels to surrender other encircled areas such as the large town of Daraya southeast of Damascus, seen for years as a stronghold of the rising against Assad.
(Reporting By Angus McDowall; Editing by Raissa Kasolowsky)
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